Odd noises from speakers

[RandallNeighbour]

I have had zero problems with my stereo system since I upgraded the head unit to an Apline unit that is wired to my factory amp and factory speakers. Not the best sound, but not the worst either.

This morning, on a quick trip from the office, the speakers started making a real racket with alternator noise (high pitched, static, etc.) as if I had not installed a noise filter on the power lead.

Then, upon startup to come back to my office five minutes later. It's gone! Everything's back to normal.

Could something be going out in my amp or head unit?

[wvicary]

Most noise in audio systems comes from a earth fault. I wouldn't worry about it unless it happens again.

[RandallNeighbour]

I have more info now. The noise rises and falls with the rpms. It also comes and goes with a bump in the road, leading me to believe it is a short in a wire somewhere.

I had an aftermarket head unit put in the car, but it was wired to the factory amp. Does anyone saavy with these issues suspect the installer put in a noise suppressor on the head unit if it was running through the factory amp?

[FrayAdjacent]

Sounds like a bad connection somewhere.